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Old 20th October 2019, 15:51   #31
racing green rover
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Mine sounds similar the system isn't pressuring no hiss when i undid the cap with the engine still hot although my heater was still warm
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Old 20th October 2019, 16:09   #32
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If there is no hiss, when you open, there is no pressure differential between the system and outside.
That is a dead give away for an open system! You have a leak where gas and water can travel. Now where? that is the question.
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Old 20th October 2019, 16:29   #33
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You have a leak where gas and water can travel. Now where? that is the question.
It's a question which has already been answered. Pete has a bleed screw which does not seal and a leaking joint between hose and pipe.

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Old 20th October 2019, 16:31   #34
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There is a really minor weep on the rubber hose from the expansion tank that joins onto the metal coolant rail, a drip from the bypass i put on to bypass the oil cooler and a really slight seep from what was the bleedscrew. Can even really tiny weeps create airlocks in the cooling system
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Old 20th October 2019, 16:57   #35
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It's a question which has already been answered. Pete has a bleed screw which does not seal and a leaking joint between hose and pipe.

Simon
Be careful not to confuse cause and effect.
A leaking bleed screw could well be the result of trying to cure another problem.
Unless of course you have one of the rare titanium plastic issue screws!
Assume really means: ASS out of U and ME
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Old 20th October 2019, 17:09   #36
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There is a really minor weep on the rubber hose from the expansion tank that joins onto the metal coolant rail, a drip from the bypass i put on to bypass the oil cooler and a really slight seep from what was the bleedscrew. Can even really tiny weeps create airlocks in the cooling system
Any loss of water, means entry of air. Accumulated air will start giving problems when it surrounds the water pump, if not before. As the pump finds only air surrounding it, it will no longer move the water around and efficient cooling is affected. This will result in overheating.
What you see as tiny, might not be under load. What you have seen so far might not be all there is!
A simple pressure pump fitted on the radiator could show some interesting results!
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Old 20th October 2019, 20:01   #37
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Yes as fluid leaks out air gets drawn in but I've had cars before that have had a water leak and despite having to top up they never had any temperature problems. Is the cooling system and waterways narrow on these cars which means air could easily get trapped.
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Old 21st October 2019, 05:21   #38
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This is not so much a case of trapped air, it is a case of too little water in the cooling system.
The Rover k series engines are in need of good cooling. This is one thing one should never take too lightly.
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Old 21st October 2019, 12:56   #39
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Quote:
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... a drip from the bypass i put on to bypass the oil cooler ...
Pete, unless you have oil and coolant mixing in the cooler, you should reconnect it.
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Can even really tiny weeps create airlocks in the cooling system
They will prevent the system from pressurising properly which results in unstable and high running temperatures. That is what you're experiencing.

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Old 21st October 2019, 15:22   #40
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The oil cooler is blocked with k seal thats why iv bypassed it im getting a used one off somebody breaking a zt180 also getting a used coolant rail with it
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